The present invention relates in general to an ion trap mass spectrometer having two separate vacuum regions allowing for use with various ionization techniques for ion production outside the spectrometer's ion trap mass analyzer. In particular, this invention relates to atmospheric pressure ionization (API) techniques (electrospray, ion spray, corona discharge etc.) for use with the ion trap mass spectrometer for direct composition analysis of liquids.
An ion spray interface for an ion trap mass spectrometer is the subject of copending application, USSN 07/889,693, filed May 29, 1992, which is hereby incorporated by reference. The interface disclosed therein permits the injection and mass analysis of ions formed at atmospheric pressure into a quadrupole ion trap mass spectrometer. With the interface, ions formed from a spray of charged solvent droplets can be injected into the ion trap mass analyzer, thereby permitting the use of condensed-phase separation science technologies, such as liquid chromatography/mass spectrometry (LC/MS), capillary electrophoresis/mass spectrometry (CE/MS) and ion chromatography/mass spectrometry (IC/MS).
One difficulty encountered when using the device set forth in USSN 889,693 for API/MS applications is that of effective ion injection and confinement in the ion trap mass analyzer.